The Internet holds great promise as a health information source for older Americans;however, little is known about older people's online health literacy. Online health literacy is the degree to which individuals have the capacity to obtain, process, and understand health information from the Internet. The main goal of the proposed research is to examine older people's online health literacy in terms of the strategies and success people have in finding accurate and useful online health information. The research's specific aims are: (1) Explore the strategies used by older adults to successfully navigate the Internet to answer typical health questions, where success is considered in terms of accuracy, perceived usefulness, and knowledge gained;(2) Assess whether older adults'online health literacy is related to gender, ethnicity, education, socio-economic status, experience with technology, and general health literacy;and (3) Compare online health literacy of older adults to that of younger adults and adolescents, determining if similar patterns exist across different age groups (where the groups are 16-21, 22-44, 45-64, and 65 and older). To address these aims, 500 participants will be recruited from the Baltimore-Washington D.C. and San Francisco regions. In media laboratories at Johns Hopkins or Stanford, participants will perform an activity where they try to find answers to open- and closed-ended health questions by searching the Internet. The research will employ innovative methods to monitor participants as they answer the questions, recording the websites visited, the applications run, and even what participants focused on when they looked at the computer screen. A subsample of 40 older adult participants will also use a talk-aloud procedure to allow the researchers to better know the participants'understanding, concerns and motivations while searching online. This research will improve our understanding of how older adults use the Internet as a health information source. The results can advance how individuals are trained to effectively use this medium, as well as inform the ways in which providers and other health care professionals communicate health messages through the Internet.